The actual existence of the plume was in some doubt until a team of researchers at Woods Hole Oceanographic Institution provided incontrovertible proof. The researchers managed to catch up with the plume about three miles southwest of the original blowout location, then used a remote-controlled submarine and an underwater spectrometer to figure out its dimensions. They were able to study the plume for ten days in June before Hurricane Alex forced them from the area. It's still not known whether this was the only plume or whether others formed, and the team said at a press conference today that they would be unwilling to commit themselves either way on that point.